1#![warn(rust_2018_idioms)]
2#![cfg(all(feature = "full", not(target_os = "wasi")))] // Wasi does not support bind()
3
4use std::time::Duration;
5use tokio::io::{self, copy_bidirectional, AsyncReadExt, AsyncWriteExt};
6use tokio::net::TcpStream;
7use tokio::task::JoinHandle;
8
9async fn make_socketpair() -> (TcpStream, TcpStream) {
10 let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
11 let addr = listener.local_addr().unwrap();
12 let connector = TcpStream::connect(addr);
13 let acceptor = listener.accept();
14
15 let (c1, c2) = tokio::join!(connector, acceptor);
16
17 (c1.unwrap(), c2.unwrap().0)
18}
19
20async fn block_write(s: &mut TcpStream) -> usize {
21 static BUF: [u8; 2048] = [0; 2048];
22
23 let mut copied = 0;
24 loop {
25 tokio::select! {
26 result = s.write(&BUF) => {
27 copied += result.expect("write error")
28 },
29 _ = tokio::time::sleep(Duration::from_millis(10)) => {
30 break;
31 }
32 }
33 }
34
35 copied
36}
37
38async fn symmetric<F, Fut>(mut cb: F)
39where
40 F: FnMut(JoinHandle<io::Result<(u64, u64)>>, TcpStream, TcpStream) -> Fut,
41 Fut: std::future::Future<Output = ()>,
42{
43 // We run the test twice, with streams passed to copy_bidirectional in
44 // different orders, in order to ensure that the two arguments are
45 // interchangeable.
46
47 let (a, mut a1) = make_socketpair().await;
48 let (b, mut b1) = make_socketpair().await;
49
50 let handle = tokio::spawn(async move { copy_bidirectional(&mut a1, &mut b1).await });
51 cb(handle, a, b).await;
52
53 let (a, mut a1) = make_socketpair().await;
54 let (b, mut b1) = make_socketpair().await;
55
56 let handle = tokio::spawn(async move { copy_bidirectional(&mut b1, &mut a1).await });
57
58 cb(handle, b, a).await;
59}
60
61#[tokio::test]
62async fn test_basic_transfer() {
63 symmetric(|_handle, mut a, mut b| async move {
64 a.write_all(b"test").await.unwrap();
65 let mut tmp = [0; 4];
66 b.read_exact(&mut tmp).await.unwrap();
67 assert_eq!(&tmp[..], b"test");
68 })
69 .await
70}
71
72#[tokio::test]
73async fn test_transfer_after_close() {
74 symmetric(|handle, mut a, mut b| async move {
75 AsyncWriteExt::shutdown(&mut a).await.unwrap();
76 b.read_to_end(&mut Vec::new()).await.unwrap();
77
78 b.write_all(b"quux").await.unwrap();
79 let mut tmp = [0; 4];
80 a.read_exact(&mut tmp).await.unwrap();
81 assert_eq!(&tmp[..], b"quux");
82
83 // Once both are closed, we should have our handle back
84 drop(b);
85
86 assert_eq!(handle.await.unwrap().unwrap(), (0, 4));
87 })
88 .await
89}
90
91#[tokio::test]
92async fn blocking_one_side_does_not_block_other() {
93 symmetric(|handle, mut a, mut b| async move {
94 block_write(&mut a).await;
95
96 b.write_all(b"quux").await.unwrap();
97 let mut tmp = [0; 4];
98 a.read_exact(&mut tmp).await.unwrap();
99 assert_eq!(&tmp[..], b"quux");
100
101 AsyncWriteExt::shutdown(&mut a).await.unwrap();
102
103 let mut buf = Vec::new();
104 b.read_to_end(&mut buf).await.unwrap();
105
106 drop(b);
107
108 assert_eq!(handle.await.unwrap().unwrap(), (buf.len() as u64, 4));
109 })
110 .await
111}
112
113#[tokio::test]
114async fn immediate_exit_on_write_error() {
115 let payload = b"here, take this";
116 let error = || io::Error::new(io::ErrorKind::Other, "no thanks!");
117
118 let mut a = tokio_test::io::Builder::new()
119 .read(payload)
120 .write_error(error())
121 .build();
122
123 let mut b = tokio_test::io::Builder::new()
124 .read(payload)
125 .write_error(error())
126 .build();
127
128 assert!(copy_bidirectional(&mut a, &mut b).await.is_err());
129}
130
131#[tokio::test]
132async fn immediate_exit_on_read_error() {
133 let error = || io::Error::new(io::ErrorKind::Other, "got nothing!");
134
135 let mut a = tokio_test::io::Builder::new().read_error(error()).build();
136
137 let mut b = tokio_test::io::Builder::new().read_error(error()).build();
138
139 assert!(copy_bidirectional(&mut a, &mut b).await.is_err());
140}
141